Experimental study of the combination of a positive input ventilation and active air vents on the air change rates of a house

This study aims to experimentally evaluate the influence of the combination of a supply only ventilation, called here positive input ventilation, and innovative active air vents on the Indoor Air Quality of a house. The positive input ventilation draws fresh air from the outside, filters and pre-heats it before blowing it in living areas. Active air vents are small motorised damper set up in upper parts of windows that can move according to local pollutants measurements or according to the measurements of the other active air vents in the house. This combination is expected to improve the Indoor Air Quality by increasing efficiently the air change rate of a room when it is too polluted. The goal of the tests presented in this paper is to evaluate quantitatively the air change rate in a real scale for different configurations of this combination. To do so, a positive input ventilation and active air vents are set up in an experimental house. The tests were carried out in 3 different rooms. For each room, the air change rate is evaluated for different configurations of the combination. CO2 is used as a trace gas to evaluate the air change rate. The results of 52 tests are used for those characterizations in order to take into account the possible variability of the results due to the real operation conditions. Results are promising and show that the studied combination enables to modulate significantly the air change rate of each room. An appropriate Demand Control Ventilation strategy based on the sensors of each active air vents and the communication between all the devices would thus lead to an efficient while simple improvement in the use of a positive input ventilation system.